Buggy code:
public Widget findWidget ( int handle ) { } public Widget findWidget ( int handle , int id ) { } public Widget findWidget ( Widget widget , int id ) { } static int fixedClassInitProc ( int g_class , int class_data ) { } static int fixedMapProc ( int handle ) { } static int fixedSizeAllocateProc ( int handle , int allocation ) { } static int rendererClassInitProc ( int g_class , int class_data ) { } static int rendererGetSizeProc ( int cell , int handle , int cell_area , int x_offset , int y_offset , int width , int height ) { } static int rendererRenderProc ( int cell , int window , int handle , int background_area , int cell_area , int expose_area , int flags ) { } void flushExposes ( int window , boolean all ) { } public Shell getActiveShell ( ) { } public Rectangle getBounds ( ) { } public static Display getCurrent ( ) { } int getCaretBlinkTime ( ) { } public Control getCursorControl ( ) { } boolean filterEvent ( Event event ) { } boolean filters ( int eventType ) { } int filterProc ( int xEvent , int gdkEvent , int data ) { } public Point getCursorLocation ( ) { } public Point [ ] getCursorSizes ( ) { } public Object getData ( String key ) { } public Object getData ( ) { } public Point getDPI ( ) { } int gtk_fixed_get_type ( ) { } int gtk_cell_renderer_text_get_type ( ) { } int gtk_cell_renderer_pixbuf_get_type ( ) { } int gtk_cell_renderer_toggle_get_type ( ) { } public static Display getDefault ( ) { } static boolean isValidClass ( Class clazz ) { } public int getDismissalAlignment ( ) { } public int getDoubleClickTime ( ) { } public Control getFocusControl ( ) { } public boolean getHighContrast ( ) { } public int getDepth ( ) { } public int getIconDepth ( ) { } public Point [ ] getIconSizes ( ) { } int getLastEventTime ( ) { } int getMessageCount ( ) { } Dialog getModalDialog ( ) { } Rectangle getWorkArea ( ) { } public Monitor [ ] getMonitors ( ) { } public Monitor getPrimaryMonitor ( ) { } public Shell [ ] getShells ( ) { } public Synchronizer getSynchronizer ( ) { } public Thread getSyncThread ( ) { } public Color getSystemColor ( int id ) { } public Cursor getSystemCursor ( int id ) { } public Image getSystemImage ( int id ) { } void initializeSystemColors ( ) { } public Font getSystemFont ( ) { } public Tray getSystemTray ( ) { } public Thread getThread ( ) { } Widget getWidget ( int handle ) { } int idleProc ( int data ) { } protected void init ( ) { } void initializeCallbacks ( ) { } void initializeSystemSettings ( ) { } void initializeWidgetTable ( ) { } void initializeWindowManager ( ) { } public void internal_dispose_GC ( int gdkGC , GCData data ) { } public int internal_new_GC ( GCData data ) { if ( isDisposed ( ) ) SWT . error ( ERROR_DEVICE_DISPOSED ) ; int root = OS . GDK_ROOT_PARENT ( ) ; int gdkGC = OS . gdk_gc_new ( root ) ; if ( gdkGC == 0 ) SWT . error ( ERROR_NO_HANDLES ) ; OS . gdk_gc_set_subwindow ( gdkGC , GDK_INCLUDE_INFERIORS ) ; if ( data != null ) { int mask = ( SWT . LEFT_TO_RIGHT ) | ( SWT . RIGHT_TO_LEFT ) ; if ( ( ( data . style ) & mask ) == 0 ) { data . style |= SWT . LEFT_TO_RIGHT ; } data . device = this ; data . drawable = root ; data . background = getSystemColor ( COLOR_WHITE ) . handle ; data . foreground = getSystemColor ( COLOR_BLACK ) . handle ; <START_BUG> data . font = getSystemFont ( ) . handle ; <END_BUG> } return gdkGC ; } boolean isValidThread ( ) { } public Point map ( Control from , Control to , Point point ) { } public Point map ( Control from , Control to , int x , int y ) { } public Rectangle map ( Control from , Control to , Rectangle rectangle ) { } static char mbcsToWcs ( char ch ) { } int menuPositionProc ( int menu , int x , int y , int push_in , int user_data ) { } public Rectangle map ( Control from , Control to , int x , int y , int width , int height ) { } int mouseHoverProc ( int handle ) { } public boolean post ( Event event ) { } void postEvent ( Event event ) { } void putGdkEvents ( ) { } public boolean readAndDispatch ( ) { } static void register ( Display display ) { } protected void release ( ) { } void releaseDisplay ( ) { } public void removeFilter ( int eventType , Listener listener ) { } int removeGdkEvent ( ) { } void removeIdleProc ( ) { } public void removeListener ( int eventType , Listener listener ) { } void removeMouseHoverTimeout ( int handle ) { } void removePopup ( Menu menu ) { } Widget removeWidget ( int handle ) { } boolean runAsyncMessages ( boolean all ) { } boolean runDeferredEvents ( ) { } boolean runPopups ( ) { } boolean runSettings ( ) { } public static void setAppName ( String name ) { } public void setCursorLocation ( int x , int y ) { } public void setCursorLocation ( Point point ) { } public void setData ( String key , Object value ) { } public void setData ( Object data ) { } int setDirectionProc ( int widget , int direction ) { } void setModalDialog ( Dialog modalDailog ) { }

Fix:
data . font = getSystemFont ( ) ;